Why don't I pass the screening processes? Don't really get it...

Hey everyone, I really need someone to shed some light here...

I dont have any idea why the top 10 BBs have screened me out without giving me the chance of an interview. I live a west European country (FR, GER, IT, SPA, SWITZ...) and I applied to all the BBs for positions in my country and London in December but I haven't got any miserable interview. I've done an extensive research and pretty much know how the industry works (at least theoretically). Also, I am graduating from a Degree in Economics from a semi-target uni with strong quantitative knowledge in 2 months and I did an internship in a mid-size hedge fund in Asia this last summer.

I am not complaining about not receiving offers. I don't even get the chance to demonstrate that I could do this job and I am willing to work my ass off! I do all the cover letters (when required) very well, including examples of buy and sell side acquisitions advised by the bank when applying for M&A role, etc.

I have networked to some alumni and I only was successful twice. Once and MD from a Tier 1 bank invited me to coffee and reviewed my CL and CV though he did not get me an interview (and that's fine, I am really grateful that he wasted his time reviewing my shit). The other time, an associate from a boutique told me he would get me an interview but then he never answered.

So, I don't get what they are looking for (BBs) when reviewing applications, I carefully read all job descriptions and I have everything they seem to be looking for. Thoughts?